Stock controlled mechanism



April 25, 1939- c. E. MILLER 2,156,157

STOCK CONTROLLED MECHANISM Filed Dec 9, 1937 3 Sheets-Sheet l g JW/WZZZY/QZZW April 25, 1939. c. E. MILLER STOCK CONTROLLED MECHANISM 3Sheets-Sheet 2 Filed Dec. 9, 1957 C. E. MILLER STOCK CONTROLLED MECHANISM April 25, 1939.

5 Sheets-Sheet 3 Filed Dec. 9, 1957 Patented Apr. 25, 1939 UNITED STATESPATENT OFFICE STOCK CONTROLLED MECHANISM Application December 9, 1937,Serial No. 178,933

13 Claims.

In the running of machines which perform operations on successivelengths or pieces of work which are successively fed into operatingposition, it is important that each length or piece be fed to a definiteposition before the operations are commenced thereon in order that suchoperations shall be performed in the proper relation to the dimensionsof the lengths or pieces. In many cases the feeding of such lengths orpieces is accomplished by some type of feeding means either yieldable orfrictional ordinarily adjusted to effect a slight over-feed in an effortto avoid the possibility of under feed, the work being fed against apositive stop at or before the end of the normal feeding action so as todefinitely position the length or article. With such a mechanism it mayoccasionally happen that the work is prevented from actually reachingthe stop and so is not in proper position to have the machine operationsperformed thereon. Under such circumstances the article would beimproperly operated upon, and should a series of tools be in operationwith a work feeding action between them, any failure to feed to thedesired extent 2 would result in improper relations between the toolingof the successive operations, spoiling the work and possibly, also,causing breakage of the tools or other parts.

In accordance with the present invention, therefore, the failure of thestock to reach the stop when such feed occurs, results in stopping themachine automatically, so that any subsequent operations after the feedare not performed until after the work has been placed in properposition. As shown and described more in detail hereinafter, this may beaccomplished by the employment of a stock stop so formed that engagementof the stock thereon after a feeding action has taken place is essentialfor continued operation of the machine.

For a more complete understanding of this invention, reference may behad to the accompanying drawings in which the invention is shown asapplied to a multiple spindle automatic lathe, though it will be evidentthat it is not limited to a machine of this particular type. In thesedrawings,

Figure 1 is a side elevation of the multiple spindle automatic latheembodying the invention. 50 Figure 2 is a section to a larger scale online 2-2 of Figure 1.

Figure 3 is a diagrammatic View of the fluid pressure and electricalstop mechanisms, the work being shown as incompletely fed toward 5 thestop.

Figure 4 is an end elevation of certain of the mechanism shown in Figure3.

Figure 5 is a section to a larger scale through the spindle nose andstock stop, the stock being shown in properly fed condition.

Figures 6 and '7 are detail sections showing a stock stop suitable fortubular work, the stock being shown in incomplete and properly fedpositions, respectively.

Referring first to Figures 1 and 2, there is shown a multiple spindleautomatic lathe of the well known Cone type, such as exemplified, forexample, in the Cone Patent No. 1,271,540 granted July 9, 1918. Thismachine, as shown, comprises a base I having upright portions 2 and 3adjacent to opposite ends and a top horizontal frame member c bridgingthe upper ends of the portions 2 and 3. Within the portion 2 ispositioned a drum orturret shown at 5 in Figure 2 which carries aplurality of rotary work spindles provided with work-engaging chucks 6at their inner ends for the reception of continuous lengths of bar stocksuch as I. This stock may be operated upon by various tools such as 8positioned at various operating stations to which the stock carried bythe several spindles is moved insequence in the usual and well knownmanner.

The frame portion 4 carries a cam shaft I0, which through suitableconnections, as is well known, controls the indexing of the turret andthe operation of the various tools which are fed in toward the work,such operating mechanism being partly shown in Figure 2. For feeding theside tools 8 the upper and lower rock arms l2 and I4 on each side may beemployed, these having actuating bars 15 and I6 which are moved andcontrolled by cams (not shown) on the cam shaft 10.

At one of the stations, shown in Figure 2 as the upper left handstation, the stock is fed into position for a start of the variousmachining operations and from this station it is passed in succession tothe other stations, the work being finally out off and discharged fromthe machine in time for the next stock feeding operation at the firststation in accordance with usual practice. The stock feed .may beproduced by any well known means which may be that shown in the ConePatent No. 2,045,070 of June 23, 1936, wherein the stock is fed byforward motion of the stock feeding tube, such as is shown in Figure 5at 20. The stock passes through this feed tube and at its forward endthe feed tube is provided with a spring gripper shown at 2| whichfrictionally engages the stock. In order that the stock may be fed tothe desired extent, it is the usual practice with feeding mechanisms ofthis type, to provide an extent of feed motion of the gripper 2|somewhat greater than that which the stock should have, the stock beingpositively stopped when it has been fed to the desired distance byimpingement on a stock stop, such a stop being shown at 25 in Figures 1,2, 3 and 5. The feeding action is resilient in order to permit the feedmotion of the stock to stop when it contacts with the stock stop andalso to prevent damage tothe parts should any obstruction prevent thefull feeding action of the stock; When the stock has been so fed, it isgripped in the chuck 6. As shown in Figure 5, this chuck may be of thecollet type, the work spindle 30 having at its forward end a taperedopening 3| which cooperates with a plurality of spring fingers 32matingly tapered externally and formed to grip the stock therebetweenwhen the collet is moved rearwardly. This motion is effected through theaxial motion of a sleeve 33 which is slidable within the spindle 30 andwhich surrounds. the stock feed sleeve 20.

The stock stop 25 is arranged to be moved into stopping position justbefore the feed is to take place and after the feed is retracted out ofthe way so that tools can operate on the projecting portion of the stockwithout hindrance from the stop. As shown in Figure 2, this stop iscarried at the outer end of a lever 46 carried by a rock shaft 4|. Thislever 40 is provided with an oppositely extending portion 42 which isconnected through a link 43 to a cam follower arm 44 fulcrumed at 45.This arm 44 has intermediate its ends a cam follower roll 46 journaledthereon, which contacts with an edge cam 47 carried by cam shaft I6, sothat when the stock is to be fed, the arm 42 is allowed to move from itsfull line position shown in Figure 2 to the dotted line position,permitting the stock stop 25 to lower into position opposite to the workspindle in the loading. station. After the stock has been fed andgripped by the chuck 6, the stop 25 is retracted to the full lineposition by the action of the cam 41.

In accordance with the present invention means. are provided by whichthe engagement. of the stock against the stop, when the stop is inoperative position, so conditions the operating mechanism of the machinethat the operation proceeds, but should the stock fail to reach itsfully fed position as determined by the stock stop, the machine stops.To this end the mechanisms shown in Figures 3, 4 and 5 have beenprovided. The machine as a whole is driven as from an .electric motor 56shown in Figures 1 and 3. While this motor may be of any suitable type,it is shown as of the three-phase induction type its energy supply beingcontrolled through a main switch indicated generally at 5| and includingswitch elements 52 for each of the three phases, and a holding coil 53,which, when energized, holds the switch closed. This holding coil isconnected to one of the phases, as54, of the supply at one .end throughthe lead 55 and at its other end connected through the switch 550 andthe lead 56 with one pole of the starter switch 51. The other pole ofthis switch 51 leads through a line 58 with the stop switch 59 andthrough a lead 60 with one pole of a normally closed switch 6|, and..anormally open switch 62. The opposite, poles of these switches 6| and 62are connected through the lead 65 with the return line of the switch 52and thus to. the phase line 54 through the overload switch 63. Theswitches 6| and 62 are therefore arranged in parallel, and the switch 6|being normally closed, normally completes the circuit through the coil53 when the starting button 51 is closed, so that the motor 56 is inoperation. The lead 58 is connected through lead 64 with the switch 550so as to cut out the starter switch 5'! when the main switch 5| isclosed. 7

At about the time in each cycle of the machine when the stock is to befed, this normally closed switch 6| is opened and held open for apredetermined period, this being accomplished as shown by a cam pin '10carried by a disk 1| secured to the rear end of the cam shaft H], whichdepresses the switch arm 72 and moves the switch contact into its openposition indicated at 13. This opening of the switch 6| would, unlessthe switch 62 were closed at that time, result in de-energizing themotor 58 and stopping the machine. However according to this invention,means are provided so that if the stock when fed moves to its fully fedposition, the switch 62 will have been closed, and held closed duringthe time'that the switch 6| is open. Means for accomplishing this may beas follows.

The stock stop 25 is provided with a fluid passage 86, which may openout on its forward face as at 8 I, this passage being suificientlysmalland in alinement with the stock S when the stop is in its stoppingposition so that the impingement of the stock against the stop closesoff the otherwise 7 open end of the passage 80. Fluid such. as oil orthe like is supplied to the passage as through a flexible pipe 82 from aline 83 which is connected into a fluid pressure operated meche, anismat 84, this in turn, being supplied with fluid through a pipe 85 from apump 86. Interposed between the pump 86 and the mechanism 84 is a reliefvalve 81 and a throttle valve 88, the valve 88 determining the rate offlow and, the relief valve 87 determining the maximum pressure which maybe maintained within the pipe 85,.

the fluid pressure mechanism 84, the pipe 83 and the fluid passage 88 inthe stock stop- When the.

stock is fed into its proper position and closes off the outlet from thepassage 86, continued operation of the pump causes a pressure tov bebuilt up within the fluid pressure pipes and passagesand this acting ona plunger 90 within a cylinder 9| of the mechanism 84 presses thisplunger 90 outwardly against the pressure of a spring 92 and intocontact with the. switch arm. 93 of the normally open switch ,62 so asto close this switch as'shown in dotted lines in Figure 3. Thus when.

the, switch 62 has been closed and held closed by the pressure of thefiuid within the cylinder 9|, opening of the switch 6| does not act toshut off the power to the motor 50, which is then energized through theswitch 62. Continuedrotation of the motor. continues the rotation of thecam shaft and thus the rotation of. the disk 1| sothat the pin 70 passesby the switch arm 12 andallows the. normally closed switch 6| to returnto closed position. Subsequent removal of the stock stop from. itsstopping position which permits the switch 62. to again open has noeffect to stop the operation of the machine. Should the stock fail toreach its fully fed position, however, the-fluid pressurepassage 38 willremain open, no pressure- 70 toopen the switch 6|, the motor 50willbecome tde-energized and the. machine will stop.

Thus the position of the plunger 90 isrespon- 7. 5;

sive to whether or not the stock has reached its fully fed position ateach feeding action, and

means actuated by the response of the plunger 90 then determines whetheror not the machine con-.

tinues to operate to perform the subsequent machining operations.

In Figures 6 and '7, a modified construction of; stop is illustratedwhich is particularly suitable: for use with tubular stock, sincetubularstock;

would permit the escape of fluid underpressure from the fluid pressurepassage 8!! of the stop illustrated in Figures 3 and 5, even though thestock were fed to fully. fed position. Referring to these figures, thestop 25 has a fluid passage 89a extending through its body portion 25landopens passage 80a may escape freely between thebody and the plate,While when the stock is in fully fed position, as shown in Figure '7,the abutment plate 253 is held up against the face 252 of the bodyportion and closes off this fiuid pressure passage 80a, this resultingin a building up of pressure which actuates the plunger 99 and closesthe normally open switch 62 when the stock is fed.

While tubular stock is shown in Figures 6 and 7, it, of course, will beapparent that this stop construction could be used with bar stock aswell as with tubular stock.

In order to facilitate the manufacture of the stock stop, its bodyportion 25! may be externally threaded for engagement within aninternally threaded socket in its supporting arm 40 and held in place asby one or twolock nuts 26!. Thebody portion may be provided with acircumferential groove to provide an annular passage 262 communicatingthrough the passage 253 with the passage 80 or 80a, and the arm 4!) maybe provided with a threaded socket 264 for reception of the end of thepipe 82 which may be secured therein through a suitable union shown at265 in Figures 3 and 5.

It will be evident, of course, that where individual articles are to befed in place of portions of a continuous stock, the action may beprecisely the same as that herein described, with the exception of theuse of a feeding mechanism suitable for individual pieces rather thanfor bar stock as shown.

From the foregoing description of certain embodiments of this invention,it will also be evident that other changes and modifications may be madewithout departing from the spirit or scope of this invention as definedby the appended claims.

I claim:

1. The combination with means for feeding stock to be worked upon towarda predetermined position, means for defining the fully fed position ofsaid stock, and means for operating on the stock so fed, of meansresponsive to the position of said stock with relation to said definingmeans, means for controlling said operating means, and periodicallyactuated means causing said controlling means to be controlled by theresponse of said responsive means, such response corresponding tofailure of the stock to reach a fully fed position acting to stop saidoperating means.

2. The, combination in a machine means for feeding stock to be workedupon to-:- ward a predetermined position, meansdefining a fully fedposition of, said stock, means forv opera,

ating on the stock so fed, and means for driving said machine, of meansresponsive to the position;

of said stock with relation to said defining means for supplying energyto said driving, means,..

means independent of said responsive means for supplying energy to saiddriving means,.and. means acting periodically to render said independentenergy supplying means inoperative during which time said responsivemeans determines such supply, said responsive means being condi-. tionedby failure of said stock to reach fully fed position to interrupt saidresponsive supply,

whereby on failure of said stock to reach fully fed position the machinestops on the next succeeding actuation of said periodically actingmeans.

3. The combination with means for feeding stock to be worked upon towarda predetermined position, means defining a fully fed position of saidstock, means for operating on the stock so.

fed, and means fordriving said operating means,

deny power, means responsive to the position of said stock with relationto said defining means,

and means controlled by said response during.

said period to condition said other controlling means to supply poweronly when said stock has. been fed in the previous feeding action fullyto said predetermined position.

4. The combination with means for. feeding, stock to be worked upontoward a predetermined. position,.a.stock stop movable from IandJtoJa,pos'ii-;.

tion in the path of feed of said stock, means for moving said stop topresent it in stopping position during the stock feed and then toretract said stop, means for operating on stock so fed, meansoperatively connected to said stop and responsive in one manner whenstock is in fully fed engagement with said stop and in another mannerwhen said stock is out of such engagement, and means controlled by suchresponse when said stop is in stopping position for energizing saidoperating means only when such response is that produced by operativeengagement of said stock with said stop.

5. The combination with means for feeding stock to be worked upon towarda predetermined position, means for operating on stock so fed, and anelectric motor for driving said operating means, of a pair ofcontrolling switches for said motor arranged in parallel, one of saidswitches being normally open and the other of said switches beingnormally closed, means effective at each stock feeding action to closeand hold closed for a period said normally open switch but only whensaid stock has been fully fed to said predetermined position, and meansacting at each stock-feeding action to open and hold open said normallyclosed switch for a time during said first-mentioned period, wherebysaid operating means fails to operate following an incomplete feeding ofthe stock to said predetermined position.

6. The combination with means for feeding stock to be worked upon towarda predetermined position, a stop against which the stock may be fed. todefine said position, and means for operating on work so fed, of meansresponsive in one manner to the operative engagement of stock againstsaid stop, and means controlled by said responsive means for preventingsubsequent operation of said operating means except when said one mannerof response has been effected at the last succeeding feed of said stock.

7. The combination with means for feeding stock to be worked upon towarda predetermined position, a stop against which the stock may be fed todefine said position, and means for operating on work so fed, of fluidpressure actuated means responsive in one manner to the operativeengagement of said stock against said stop, and means controlled by saidfluid pressure actuated means for preventig subsequent operation of saidoperating means except when said one manner of response has beeneffected at the last succeeding feedof said stock.

8. A machine comprising means for periodically feeding stock to beoperated upon toward a predetermined position, a stop against which the.stock may be fed to define said position, said stop having a fluidpassage therethrough closed when; the stock is in fully fed positionwith respect thereto, means for operating on stock after each, feedingaction, and means effective to prevent subsequent action of saidoperating means whensaid fluid passage has not been closed during thenext preceding stock feed.

9. A machine comprising means for periodically feeding stock to beoperated upon toward a predetermined position, a stop against which thestock may be fed to define said position, said stop having a fluidpassage therethrough closed when the stock is in fully fed position withrespect thereto, means for supplying fluid to said passage to build uppressure when said passage is closed, a fluid pressure actuated meansoperatively connected to said passage, and means dependent ontheactuation of said fluid pressure means at each feeding actuation of thestock for producing subsequent operation of said operating means.

10. A machine comprising means for periodically feeding stock to beoperated upon toward a predetermined position, a stop against which thestock may be fedto define said position, said stop having a fluidpassage therethrough closed when the stock is in fully fed position withrespect thereto, means for supplying fluid to said passage to build uppressure when said passage is closed, a fluid pressure actuated meansoperatively connected to said passage, an electric motor for actuatingsaid operating means, a pair of controlling switches for said motorarranged in parallel, means automatically opening and there holding oneof said switches for a time at each feed actuation, and operativeconnections for closing andholding closed the other of said, switches bythe actuation of said fluid pressure actuated means during the time saidone switch is open.

11. A stock stop having a fluid'passage therein, and a portion forengagement with stock fed thereagainst, said stop including meanscausing pressure of stock against said portion to close said passage.

12. A stock stop comprising a member having a face against which a faceof stock to be stopped may be engaged, said member having a fluidpassage opening through said member face within the area of said stockface in position to be closed off when the stock engages said mem-. ber.

13. A stock stop comprising a member having a fluid passage opening outat one face thereof, and an abutment carried by' said member for motiontoward and from said face, said abutment having an inner face closingoff said passage when in engagement with said face, and being positionedto be pressed into such engagement by stock fed against its outer face.

' CARROLL E. MILLER.

